The standing long-term goal of this research direction has been to understand the molecular and physiological processes that lead to aging in the nematode Caenorhabditis elegans. I have found three new alleles of age-1 which is a gene that extends life span. We propose to identify the molecular and physiological bases of these life-prolongation effects and to directly test the hypothesis that prolongation of life span results from the enhancement of processes mediating the ability to withstand toxic stress. My aims are to (A) finish backcrosses, complemenation tests and mapping of the newly isolated Age mutants; (B) test for the stress- resistant phenotypes (thermotolerance, UV resistance, and H2O2 resistance) of each of these strains; (C) if mutants show increased thermotolerance, determine whether hsp-16 is more readily induced, as is the case for age- 1; and (D) assess behavior, development and other life history traits on the new Age mutants.